Methods for wire terminal forming



June 12, 1962 R. o. DEXTER METHODS FOR WIRE TERMINAL FORMING Original Filed June 19. 1957 2 Sheets-Sheet 1 In we n tar Ric/land D Dexzer- June 12, 1962 R. D. DEXTER 3,038,245

METHODS FOR WIRE TERMINAL FORMING Original Filed June 19, 1957 2 Sheets-Sheet 2 [4 I x t f J Z6 33 A E kiiuu Inventor Richard D. Dexzer By hi y Patented June 12, 1962 ice 3,038,245 METHODS FOR WIRE TERMINAL FURMING Richard D. Dexter, Beverly, Mass, assignor to United Shoe MachiueryCorporation, Boston, Mass, 2 corporation of New Jersey Original application June 19, 1957, Ser. No. 666,621, now Patent No. 2,946,368, dated July 26, 1960. Divided and this application Apr. 9, 1959, Ser. No. 805,327 3 Claims. (U. 29-15555) This application is directed to a novel method of forming a wire terminal such as disclosed in my copending application Serial No. 666,621, filed June 19, 1957, now issued as United States Letters Patent No. 2,946,368, dated July 26, 1960, land of which this application is a division.

This invention relates to the art of applying eyelettype connectors to the ends of electrical wire conductors, and more particularly to the secure attachment of such a connector to form an electrical conductor terminal on the end of a multiple strand wire conductor.

Examples, illustrating the present manner of applying eyelet-type terminal connectors, are disclosed in several United States patents, including the following: Patent No. 1,677,968, W. Hughes; Patent No. 2,296,983, Cooper et al.; and Patent No. 2,530,575, S. L. Gookin. As disclosed in the above patents, it heretofore has been customary first to form an eye or loop on the end portion of the wire connector, then to insert an eyelet barrel within the preformed loop and finally to upset the eyelet barrel, so that it is progressively split longitudinally, each split portion being deflected by an eyelet setting anvil member outward and upward to embrace the wire strands of the loop and to clench the wire between the eyelet flange and the upset barrel portions. Another manner of forming such a connector is disclosed in US. Patent No. 2,756,802, S. L. Gookin, whereby the wire loop is formed by first splitting a single section of the barrel and clenching it around an end portion of the conductor wire, then rotating the eyelet a sulficient amount to cause the wire to form a wrapped loop about the barrel, whereupon the rest of the barrel is upset to embrace the wire of the loop. Although the above semiautomatic machines have been provided with means for forming the end or loop to be embraced by the upset portions of an eyelet barrel, in each instance special machinery was required to form the end of the wire into a loop, and special attention was necessary on the part of the operator in order to present the proper portion of the wire end to the loop forming machinery. Therefore these prior machines were not only costly but required expert handling on the part of the machine operator.

Another difiiculty heretofore encountered was that the eyelet connector terminal thus attached, if not subsequently subjected to a dip soldering operation, had a tendency to pull out readily from the conductor wire if the latter were tensioned after the terminal had been secured to a fixed electrical mounting, such as a binding post. This disadvantageous tendency is due to the fact that the wire is wrapped to form the loop in only one direction and, therefore, as a tensioning pull is exerted on the conductor, there is a unidirectional force tending to unwrap the wire or to rotate the eyelet. Substantially all of this force is concentrated upon the first split portion of the eyelet barrel that embraces the wire. This portion which is nearest in the direction of the tensioning pull, will become unclenched and then the next adjacent split barrel portion will be subjected to the same concentration of force tending to unwind the wrapped loop of wire; thus the holding power of the terminal is progressively weakened until the wire is completely pulled out from the eyelet.

One of the objects of the present invention is to provide a method, and means to be applied to any eyeleting machine, for forming a wire conductor end into a curved bight or divided loop through which an eyelet barrel may be inserted and then clenched upon the strands of the wire.

Another object is to provide a novel method and means for applying an eyelet-type connector to form a wire terminal of greatly increased holding power, and of such a formation that the above-described rotative force tending to unwrap the wire from around the eyelet is eliminated, by so dividing any tensioning pull upon the wire conductor that the forces are evenly distributed in both directions around the split portions of the upset barrel.

Another object of the invention is to provide a method and means whereby relatively heavy stranded conductor wires having increased wire diameters may be clenched satisfactorily by using much smaller eyelets than could be clenched around the same wire if the wire end or loop were formed by heretofore known means.

A further object of the invention is to provide a novel method and means that require no expert handling of the wire on the part of the opera-tor when presenting the end of the wire to the operation of a machine.

One feature of the invention is that the wire strands that are curved around the pilot spindle are adequately confined within the radial limits of the eyelet flange so that in the upsetting of the barrel portion and the clenching operation every strand of wire is gathered inward by the split portions of the barrel as they are curled outward and upward around the strand.

Another advantageous feature which is attained by my novel method and means of forming the connector terminal is that the finished terminal is substantially thinner or flatter in heightwise cross section than would be the case if the same eyelet and wire had been clenched by previously known means. This is a particular advantage when it is desired to mount a number of terminals in superimposed relation upon a single binding post.

The above and other advantageous features of this invention will be more fully understood and appreciated when considered with the following detailed description in connection with the drawings, and will be pointed out further in the claims.

In the drawings:

FIG, 1 is a perspective view of a portion of an eyelet inserting machine adapted to perform my novel wire terminal attaching method;

FIG. 2 is an enlarged view showing the details of mechanical means for forming a divided loop on the end of a wire;

FIGS. 3 and 4 are top plan views showing progressive stages by which a divided loop may be manually formed on the end of the wire;

FIGS. 5 and 6 are side elevational views, partly in section, showing the progressive stages by which an eyelet is automatically inserted through the loop and finally clenched to form a terminal connector in accordance with the invention;

FIG. 7 is a top plan view partially in section, showing a clenched terminal when viewed along the section line VIIVII of FIG. 6; and

FIG. 8 is a view of a completed terminal as viewed from the bottom or opposite side from that illustrated in FIG. 7.

Referring to the drawings, and particularly to FIGS. 1 and 2, the invention is herein illustrated as performed in an eyelet setting machine of a well-known type whereby the eyelets are set by pressure applied axially upon each eyelet while positioned between two relatively movable anvils in the form of set dies. Due to the well-known construction of such machines, whether manual or power operated, only so much of the machine has been illustrated, and will be described hereinafter, as is necessary for an understanding of the present invention. A reciprocating plunger rod 10, journaled through a forward portion of the machine frame 12, is driven in a vertical path by any suitable power means or by a foot treadle. The rod has secured to its lower end an upper set cap assembly 14 provided with a coaxially disposed spindle 16 which is retractably mounted in the assembly. The eyelets to be set or clenched to the end of the conductor wire are supplied by means of a raceway, the lower end of which is illustrated as 18. When in the at rest position of the machine the upper set cap assembly is elevated so that the lower end of the spindle 16, which is spring biased to protrude downward beyond the anvil surface of the upper set cap assembly 14, is above the level of the raceway end, and the spindle is in axial alinement with the barrel of the endmost eyelet E in the bottom of the raceway. Upon actuation of the machine, the spindle 16 descends and enters the barrel of the eyelet E. While the eyelet is thus impaled by the spindle, the raceway is retracted to one side to strip the end most eyelet from the raceway and to clear the path for the further descent of the spindle which then carries the eyelet downward to place the lower end of the eyelet barrel in contact with a lower set die having an annular upsetting anvil 20 above which protrudes a pilot pin 22 for centering the eyelet during the setting operation. The anvil 20 is rigidly affixed to a frame portion of the machine, and the front of the pilot pin 22 is formed with tapered surfaces 24, 24, which at their common junction provide a sharp vertical knife-like edge 26 facing the operators position. The lower anvil member 20 is closely confined Within ,a coaxial sleeve 28 that is spring biased, by a spring 30,

so that it normally extends a substantial distance above the clenching surface of the anvil, as illustrated in FIG. 2. This sleeve 28 is relieved at its upper forward face providing an opening 32 through which the bared end of a stranded wire W may be manually inserted to impinge endwise against the sharp edge 26. The downwardly yieldable sleeve 28 is attached to the anvil member 20 by a screw headed pin 34 passing through a longitudinal guide slot 36 in the wall of the sleeve, thus permitting the sleeve normally to be projected upward by the spring 30 so as to provide a confining wall around the anvil 20 and its associated pilot pin 22. However, as the upper set die 14 approaches the lower anvil 20 during the operative stroke of the plunger rod 10, the die 14 abuttingly engages the upper rim of the sleeve 28 to depress the sleeve against the force of the spring 30, FIGS. 5 and 6. Also, during the approach of the dies 14, 20, the pilot pin 22 engages the lower end of the yieldable spindle 16 causing the latter to become progressively retracted to within the die assembly 14 so that the eyelet barrel is transferred from its impaled relation upon the spindle 16 to a similar relation upon the pilot pin 22 which then acts to center the eyelet and, in conjunction with the anvil surface 20, to cause the barrel portions to be split and deflected outward and upward against the inner wall of the confining sleeve 28.

To form a connector terminal in accordance with the present method, the bared end of a multistranded electrical conductor wire is presented, by the operator to the illustrated machine in the following manner. With the machine in the at rest position, the bared end of the wire is placed through the space 32 of the sleeve 28 and is pressed endwise against the sharp edge 26 of the pilot pin, FIGS. 2 and 3, so that substantially half of the wire strands are disposed at either side of the edge 26. The wire is then continuously advanced endwise against the pin causing the edge and the tapered surfaces 24, 24, to divide the strands into two groups which are progressively deflected in diverging paths, FIG. 4, until the respective ends of the strands engage the inner wall of the confining sleeve 28, whereupon the ends are deflected or curved progressively into a converging path to form a divided loop substantially surrounding the pilot pin 22.

Having thus first formed the loop or curved bight on the end of a conductor wire, the machine is then actuated to insert an eyelet barrel through the loop in the conventional manner. As the lower lip of the eyelet barrel is forced down over the pin 22, and before the barrel commences to be split apart, the lip of the eyelet enters between the pilot pin and the loop. It is to be noted in the illustrations of FIGS. 5, 6, and 8, that the preformed flange portion F of the eyelet is provided with a diameter suificient to overlie a portion of the rim of the sleeve 28, so that the diameters of both the annular lower anvil 20 and the bore of the sleeve 28 are less than that of the flange portion F. As a consequence thereof, as the barrel of the eyelet is progressively split and curled upward to be finally clenched under the flange, the strands of wire which form the divided loop are all confined, by the inner sleeve wall, to an over-all diameter smaller than that of the eyelet flange. Therefore, as the split portions of the barrel embrace the strands and are clenched against the lower surface of the flange F, the individual wire strands are tightly confined, FIG. 8, to a zone Well within the diameter of the finished connector terminal.

From the foregoing description of the manner by which the conductor terminal is formed, and from a consideration of the finished terminals, FIGS. 6, 7 and 8, it will be readily perceived that, as above related, any tensioning force applied to the wire W tending to pull the wire free from the clenched eyelet will be evenly divided in both directions around the split barrel portions, thus substantially doubling the holding power of the eyelet upon the strands of wire.

It is also obvious that if the wire for forming the divided loop is properly divided on either side of the loop, fewer strands need be embraced by any given portion of the eyelet and therefore a much tighter clench can be obtained. This feature results not only in far greater holding power per strand but in a much thinner finished connector.

It is to be noted that whereas the foregoing detailed description is related to the use of mechanical machinery for carrying out my novel method, other means may be employed. For instance, the bared end of wire strands may be divided or split into two groups manually by pressing the ends against any suitable tool having a wire strand dividing edge of wedge shape. Then with the wedge shaped tool still holding the two groups of strands apart, the end portions of each group may be bent or manually deflected together so as to form the desired closed loop. Finally, the wire with the looped end may be removed from the tool and an eyelet set in the preformed loop by any conventional eyelet setting means.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of forming a wire terminal connector on the end of a multistranded electrical conductor wire which comprises the steps of: placing a bare end of the wire substantially perpendicular to and against a sharply defined spindle edge, formed by the junction of two tapering surfaces, so that the ends of substantially half of the strands are disposed adjacent either side of said edge; forcefully pressing the wire axially to advance it continuously against said edge, causing the end of the strands to be divided by the edge into two groups; continuing the pressing of the wire against the edge, causing the tapering surfaces to deflect each group of strands progressively during their advance into diverging paths along and beyond said surfaces; causing the ends of the strands beyond said surfaces to be curved by deflection into a converging path until the ends of the respective strands in each group substantially meet each other to form a divided loop on the end of the wire; discontinuing the advancement of the wire inserting an eyelet barrel through the divided loop; and clenching the eyelet barrel around the wire strands of the loop.

2. The method of forming an electrical terminal con nector on an end of multi-stranded wire, comprising the steps of: advancing the wire in a continuous movement lengthwise of its axis while dividing the strands at said end of the wire into two distinct groups each containing substantially half the strands; simultaneously deflecting both groups, in substantially the same plane, away from each other with each group moving away from the axis of the wire at an acute angle; continuing the axial advancement of the wire to deflect successive portions of both groups away from each other and the axis of the wire; in said continuous movement, deflecting the then diverging ends of both groups toward each other in a curvilinear path; deflecting the ends of the groups into substantial abutment, thereby to form a divided loop; discontinuing the advancement of the wire and finally clenching an eyelet barrel through said loop and around the divided strands.

3. The method of forming an electrical terminal connector on an end of multi-stranded wire, comprising the steps of: placing the end of the wire substantially perpendicular to and against a sharply defined spindle edge, formed by the junction of two tapering surfaces, so that the ends of substantially half of the strands are disposed adjacent either side of said edge; advancing the wire in a continuous movement lengthwise of its axis while dividing the strands at said end of the wire into two distinct groups each containing substantially half the strands; simultaneously deflecting both groups in substantially the same plane away from each other, with each group moving away from the axis of the wire at an acute angle; continuing the axial advancement of the wire, thereby to cause the tapering surfaces to deflect each group of strands progressively during their continuous advance into diverging paths along and beyond said surfaces; in said continuous movement, deflecting the then diverging ends of both groups toward each other in a curvilinear path until the ends of the respective strands in each group are deflected into substantial abutment, thereby to form a divided loop; discontinuing the advancement of the wire; and finally clenching an eyelet barrel through said loop and around the divided strands.

References Cited in the file of this patent UNITED STATES PATENTS 1,751,405 Herman Mar. 18, 1930 1,953,476 Gilbert Apr. 3, 1934 2,461,994 Merkel Feb. 15, 1949 2,760,195 Berg Aug. 28, 1956 FOREIGN PATENTS 23,891 Great Britain of 1910 

